The main antigen of the microsomal fraction of thyrocytes is thyroid peroxidase.
Microsomes are located inside the epithelial cells surrounding the thyroid follicles. In pathology, they become antigens, they synthesize antibodies that damage the cells of the thyroid gland. Fibrosis of the thyroid gland develops and its function decreases. Hypothyroidism often develops. Antimicrosomal antibodies (AMC) are a determining factor in Hashimoto autoimmune thyroiditis.
The main antigens of the thyroid gland are thyroid peroxidase, thyrotropin receptors and thyreoglobulin. In addition to thyroid peroxidase, other antigens may be present in the microsomal fraction of thyrocytes. Therefore, the definition of AMS is particularly important in screening the population and identifying people at high risk for developing autoimmune thyroiditis.
These antibodies are detected in 95% of patients with Hashimoto thyroiditis and in 70% (and above) of patients with diffuse toxic goiter, where their presence, on the one hand, may be a reflection of a polyclonal autoimmune attack against thyrocytes, and on the other, indicates the presence of lymphocytic infiltration, which can later lead to destruction of the gland and the transition of hyperthyroidism into hypothyroidism. In patients with a multinodal euthyroid goiter, which itself is not considered an autoimmune disease, the presence of AMC in the blood (but not thyroglobulin antibodies) indicates lymphoid infiltration of the near-nodular thyroid tissue or focal thyroiditis. These data demonstrate the prognostic value of AMC and the need for their determination in any disease of the thyroid gland.
The definition of AMC is necessary for any endocrine pathology, especially for diabetes mellitus or polyendocrine syndrome (Schmidt syndrome), given the frequent combination of these diseases and autoimmune diseases of the thyroid gland.